Python OpenCV : Reading an image along x and y axis

Question

目标:我正在尝试读取此图像中的第一个点(非零点)(显示为红色箭头)

from __future__ import division
import numpy as np

import cv2
im1 = cv2.imread('C:/Users/Desktop/Line.png', 0)
for x in range(0, im1.shape[0], 1):
    for y in range(0, im1.shape[1], 1):
        cpt = im1[x][y]
        if 0 < cpt <= 255 :
           print("This is the value", x,y)

但是，打印的点是这个(零点):

怎么会这样？

原始图像:

Answer 1

如果你的图像很干净(没有噪点)，那么试试这个:

import cv2
import numpy as np
img = cv2.imread("JKNp9.png")
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
ys,xs = np.nonzero(gray)
idx = np.argsort(xs)[0]

pt = xs[idx], ys[idx]

print(pt)
cv2.line(img, pt, pt, (0,255,0), 3, cv2.LINE_AA)
cv2.imshow("img", img)
cv2.waitKey()

---

pt 是:(27, 388)

就是这样: